PHP | openssl_public_encrypt() Function

Hello folks! welcome back to a new edition of our tutorial on PHP. In this tutorial guide, we are going to be studying about the PHP openssl_public_encrypt() Function.

The openssl_public_encrypt() function is used to encrypt the data with public key.

This built-in function encrypts the data and it can be decrypted using the built-in PHP openssl_private_decrypt() function.

syntax

Following below is the syntax to use this function -

openssl_public_encrypt ( string $data , string &$crypted , mixed $key [, int $padding = OPENSSL_PKCS1_PADDING ] ) : bool

READ: PHP | openssl_pkey_get_private Function

Parameter Details

Sr.No	Parameter	Description
1	data	.
2	encrypted	It will have the data that is encrypted.
3	key	The public key.
4	padding	The padding you can apply are : OPENSSL_PKCS1_PADDING, OPENSSL_SSLV23_PADDING, OPENSSL_PKCS1_OAEP_PADDING, OPENSSL_NO_PADDING.

Return Value

This PHP function returns true on success or false on failure.

PHP Version

This PHP function works from PHP version greater than 5.0.0.

Example1

The following example illustrates the usage of PHP openssl_public_encrypt() function to encrypt data using Public Key -

<?php
   // Save Private Key
   $privkey = openssl_pkey_new();
   openssl_pkey_export_to_file($privkey, 'C:/xampp/htdocs/modules/openssl/privatekey.pem');
	
   //Save Public Key
   $dn = array(
      "countryName" => "NG",
      "stateOrProvinceName" => "Rivers",
      "localityName" => "test1",
      "organizationName" => "test2",
      "organizationalUnitName" => "test3",
      "commonName" => "www.test.com",
      "emailAddress" => "xyz@test.com"
   );
   $cert = openssl_csr_new($dn, $privkey);
   $cert = openssl_csr_sign($cert, null, $privkey, 365);
   openssl_x509_export_to_file($cert, 'C:/xampp/htdocs/modules/openssl/publickey.pem');
	
	
   // To encrpt data
   $data = 'Welcome To WebDesignTutorialz';
   $isvalid = openssl_public_encrypt ($data, $crypted , file_get_contents('C:/xampp/htdocs/modules/openssl/publickey.pem'),OPENSSL_PKCS1_PADDING);	
   echo "Data encryption : ".$crypted;
?>

Output

When the above code is executed, it will produce the following result -

Data encryption : ��E �wC�ݭ�+c��f*��o���W�7�EW��$�p�.rng�_N��A1��2Uݴ~s�ap۳)w��=� ��#��g;�
��u��_%�Z�bb�&��m��v&����q��k

Example2

The following example below illustrates the usage of the openssl_public_encrypt() and the openssl_private_decrypt() functions for encrypting and decrypting data -

<?php
   // Save Private Key
   $privkey = openssl_pkey_new();
   openssl_pkey_export_to_file($privkey, 'C:/xampp/htdocs/modules/openssl/privatekey.pem');
	
   //Save Public Key
   $dn = array(
      "countryName" => "NG",
      "stateOrProvinceName" => "Rivers",
      "localityName" => "test1",
      "organizationName" => "test2",
      "organizationalUnitName" => "test3",
      "commonName" => "www.test.com",
      "emailAddress" => "xyz@test.com"
   );
   $cert = openssl_csr_new($dn, $privkey);
   $cert = openssl_csr_sign($cert, null, $privkey, 365);
   openssl_x509_export_to_file($cert, 'C:/xampp/htdocs/modules/openssl/publickey.pem');
	
	
   // To encrpt data
   $data = 'Welcome To WebDesignTutorialz';
   $isvalid = openssl_public_encrypt ($data, $crypted , file_get_contents('C:/xampp/htdocs/modules/openssl/publickey.pem'),OPENSSL_PKCS1_PADDING);	
   echo "Data encryption : ".$crypted;
   echo ">br/<>br/<";
	
   if ($isvalid) {	
      openssl_private_decrypt ($crypted, $decrypted , file_get_contents('C:/xampp/htdocs/modules/openssl/privatekey.pem'),OPENSSL_PKCS1_PADDING);	
      echo "Data decryption : ".$decrypted;
   }
?>

Output

When the above code is executed, it will produce the following result -

Data encryption : L�_}{�E*?��9[w��7p �\ϸI�?ݟ'��ݹ�n��!��ɿ�*��Xcw���Ւ�)��/��{��!j�L��I*Ï"9eV�9�=Y\�m�i䁦�M(�0PJ��Ԇ�9��C�`�a�ݧ�b��a��?�m�G$i��eU/[�eU����\=�zLdŌn"��:[\�UA��ԭ�ힲ2@-"d��s�=2�nˣ�h��q5U��浿��9�{ݼ��|�NE�a!

Data decryption : Welcome To WebDesignTutorialz

READ: PHP | openssl_private_encrypt() Function

Alright guys! This is where we are going to be rounding up for this tutorial post. In our next tutorial, we will be studying about the openssl_public_decrypt() Function.

Feel free to ask your questions where necessary and we will attend to them as soon as possible. If this tutorial was helpful to you, you can use the share button to share this tutorial.

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Thanks for reading and bye for now.